Frequencies for first 10,000 rows of tow_veh variable in person dataset :

      TOWED |
   TRAILING |
       UNIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,683       86.83       86.83
          1 |        403        4.03       90.86
          2 |         34        0.34       91.20
          3 |         10        0.10       91.30
          4 |          4        0.04       91.34
          9 |        106        1.06       92.40
          . |        760        7.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016